Everything is about risk — as everyone above me has stated, its all about whether the good will outweigh what might possibly go wrong. Therefore, a good PM must be able to analyse and handle the risk in the most efficient way possible:
1. Identify the risk: What is it? Where is it coming from?
2. Analyze the risk: What exactly does the risk entail? What are the details?
3. Evaluate or rank the risk: Is it necessary to take it? Can you avoid it altogether?
4. Treat the risk: How can it be fixed or worked around?
5. Monitor and review the risk: How well has the risk management worked? Has the risk been contained? Will it pose something larger in the future? Will that be manageable?